I use their wallflowers all the time and love them. I only order online although we have a store within an hour's drive from me. All the fragrances in their stores put my smell sense in a tailspin and I get overwhelmed. I've found that when I order the "new" refills, they're a bit more strong. I've just recently started using their liquid hand soaps and like them, too.
As for customer service, I received an order once in which one bottle had come open and leaked. I called CS just to let them know and had to have a discussion with them that I only wanted them to know of the issue; they wanted me to keep the entire order (I usually order 10-12 at a time) and they wanted to replace the order. That impressed me, although I didn't take them up on their offer. Replacing an entire $40+ order for one $4 item seemed like I was ripping them off.
I have noticed an issue with some of their wallflower plugs that leak with age. I'm not a fan of the highly decorated ones and don't care for the night light option, so the ones i get are inexpensive; that may be the problem.